8167 posts · Joined 2013. #6 · Jun 1, 2019. The watch is probably defective. I had a GW500 (the predecessor of this watch with 5 multi bands instead of 6 like the GWM500A has) and the module became faulty and the adjust button stopped working. However i cannot see anybody needing to open the watch, It is solar. Daylight Saving Time (DST)/Summer Time Adjustment | CASIO. My Account; Sign Out please correct the time according to the operation of the Quick Operation Guide .

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